Relationship Between Carburization and Zero-Applied-Stress Creep Dilation in Alloy 800H and Hastelloy X

摘要

Typical HTGR candidate alloys can carburize when exposed to simulated service environments. The carbon concentration gradients so formed give rise to internal stresses which could cause dilation. Studies performed with Hastelloy X and Alloy 800H showed that dilations of up to almost 1% can occur at 1000 exp 0 C when carbon pickup is high. Dilation was normally observed only when the carbon increase was >1000 mu g/cm exp 2 and ceased when the diffusing carbon reached the center of the specimen. (ERA citation 06:020202)